Spark plug



July 16, 1929 J. F. DORGAN ET AL 1,721,435

SPARK PLUG Filed Feb. 18, 1928 2 sheets-Sheet l ATTO R N EY July 16, 1929. J. F. DoReAfi ET AL SPARK PLUG Filed Feb. 18, 1928 2 Sheets-Sheet 2 INVENTOR ATTORN EY Patented July 16, 1929.

6F F lCIE JEREMIAH. F. DORGAN AND VICTOR ALES, OF OSSINING, NEW YORK, ASSIGNORS OF ONE- THIRD T WILLIAM THOMAS COBB, OF OSSININ G, NEW YORK.

SPARK -PLUG.

Application filed February 18, 1928.

Our present invention has reference to spark plugs for internal combustion engines and our primary object is to provide a spark plug of a simple construction which will be positive in action and which is provided with means for quickly correcting any miss in the spark due to any plug trouble.

A further object is the provision of a spark plug that shall embody in a practical manner means by which an operator can change the porcelain while the motor is running at any speed, and means whereby the compression generated by the use of the piston in its travel will be controlled or prevented from escaping through the piston cylinder, such compression also assisting the removal of the porcelain, which may be ac complished by the fingers of the operator and without the employment of instruments.

A still further object is the provision of a spark plug in which the gap between the electrodes may be easily adjustethand further wherein the terminals of the conductor wires will be quickly clamped upon or readily removed from the plug.

To the attainment of the foregoing and other objects which will appear as the nature of the invention is better understood, the improvement consists in the novel features of.

construction, combination and operative association of parts, one satisfactory embodiment of which is disclosed by the accompanying drawings, will be described in the accompanying specification and specifically set forth in the appended claims.

In the drawings:

Figure 1 is a side elevation of our improvement.

Figure 2 is a substantially central sectional longitudinal view therethrough.

Figure 3 is a top plan view thereof.

Figure t is a detail elevation of the upper portion of the plug showing the manner in which the terminal wires may be readily attached to or removed from the plug.

Figure 5 is a sectional view through the lower portion of the plug with the porcelain removed.

Figure 6 is a sectional view on the line 66 of Figure 5.

Figure 7 is a sectional view on the line 77 of Figure 5.

Figure 8 is a perspective view of the valve which also provides the ground electrode,

Serial No. 255,441.,

the parts constituting the same being dis-- associated.

Figure 9 is a sectional view approximate ly on the line 9-9 ofFigure 8.

Figure 10 is a side elevaton of the spring employed.

Figure 11 is a perspective view looking toward the upper portion of the plug.

The metal shell 1 of our improved spark plug has its lower portion shouldered and formed with the usual threaded extension that is screwed in the spark plug opening in the head 2 for the engine block. The reduced threaded portion 3 of the improvement has its end flared inwardly, as at 4, to provide a seat for a valve which will presently be described. There is a shoulder 5 between the flared wall. or valve seat 4 in the inner bore of the shell, and also the shell has an outer enlarged bore extension providing an inner shoulder 6.

Received through the opening provided in the shouldered portion 5 of the shell, there is a tubular or sleeve portion 7 of the improvement. The upper end of this sleeve is formed with a head 8 and the inner wall provided by the head is flared, as at 9. The head provides a valve which is designed, when the porcelain of the improvement (hereinafter to be described) is removed, to occupy the seat 41-.

Screwed on the upper end of the tubular stem or sleeve 7 there is the nut member 10. This nut member is round in plan and is designed-to rest on the shoulder 6 on the shell. Surrounding the tubular stem or sleeve 7 and exerting a tension between the shoulder 5 in the shell, there is a'helical spring 11 which, of course, urges the sleeve through the bore of the shell and tends to bring the valve 8 on its seat 4: and thereby close the bore through the shell to prevent compresslon in the piston cylinder in which the plug is arranged from escaping therethrough, such compression being, of course, caused by the reciprocation of the piston in the cylinder.

The tubular stem or sleeve 7 is, directly above and in a line with the head 8, provided with oppositely disposed ports or openings 12 that provide gaps for the spark created by the plug.

The porcelain of the improvement is indicated by the numeral 13 and is formed with an enlargement which provides a lower shoulder 14 designed to rest on the nut 10 and an upper and flared shoulder 15. This flared shoulder is designed to be contacted by a copper gasket 16 and the said shoulder is forced against the shoulder 14 when the packing nut 10 is screwed in the bore at the outer end of the shell. Obviously, the packing nut will hold the porcelain in the shell and-will cause the valve portion 9 of the head 8 to be unseated.

Passing centrally through the porcelain there is a metal rod that provides the power electrode of the improvement. This rod, indicated by the numeral 18, has both its ends threaded, and screwed. in the end thereof that is received through the tubular stem or sleeve 7, there is a nut 19 which contacts with he inner end of the porcelain. I The rod 18 is adjusted to arrange the same the proper space from the inner wall of the straight head 8 to afford the necessary spark gap between the said rod 18 and the head which provides the ground electrode of the plug.

Screwed on the outer end of the power electrode or red 18 and contacting with the upper end of the porcelain 13, there is a flat nut or washer 2t), and arranged around the rod or electrode and contactin the said nut er washer there is a light coil spring 21. The spring 21 has its outer convolution in contact with a metal cup member 22 which is freely arranged on the rod or electrode 18, and against which there is designed to be seated a terminal 23 for a conductor wire 2%.

There is screwed on the outer end of the rod or electrode 18 a sleeve n'iember 25. This sleeve has laterally extending short lugs or trunnions 26 which are received in bearing openings in the side members of a fork 27. The central or connecting element for the fork has a threaded stem on which is screwed a wooden handle 28. The outer or free ends of the arms of the fork are directed a considerable distance away from the pivot lugs or trunnions 26 and these ends of the said rods are rounded. The arms of the fork straddle the terminal 23, thereby swinging the lever or handle 28 to bring the fork into longitudinal alinement or in a plane with the electrode 18. It will be seen that the rounded ends of the said fork contacting with the cup member 22 will depress the same on the rod 18 against the pressure of the spring 21, so that the terminal 23 for the Wire 2 1 may be easily connected to or removed from the plu From the foregoing description, when read in connection with the accompanying drawings, it will be seen that the spark plug offers a departure from the regular plugs now in use. Our plug has an automatic spark gap and the porcelain is detachable when the motor is running, allowing any operator to correct a miss in his motor, due to ignition trouble in his plugs. It is not necessary to in any way change the build or shape of the motor as our plugs will be made in the varying standard sizes now in use. The construction and advantages of the plug will, it is thought, be fully understood and appreciated by those skilled in the art to which the invention relates, but obviously we do not wish tobe restricted. to the precise details herein set forth, and, therefore, hold ourselves entitled to make such changes therefrom as fairly fall within the scope of what we claim.

Having described the invention, what we clain'i is:

1. A spark plug having a ground electrode which is spring influenced toward the shell of the plug and held by the power electrode arrying porcelain away from the plug and which is automatically movable to close the shell. when the porcelain is removed from the I shell.

2. A spark plug having a headed ground electrode in one end thereof, spring means influencing the ground electrode to move the head thereof against the inner end of the shell, and a power electrode carrying porcelain designed, when seated in the shell, to hold the head of the power electrode a predetermined distance from the shell and when said porcelain is removed. from the shell to permit the spring means to influence the ground electrode to contact with and close the shell.

In testimony whereof we aflix our signatures.

JEREMIAH F. DORGAN. VICTOR ALES. 

